Ionic migration and charge reduction in Ni2+-, Co2+- and Zn2+-exchanged Texas montmorillonite

Autor:	Lu Yun, J. H. Purnell
Rok vydání:	1993
Předmět:	Inorganic chemistry Oxide Ionic bonding General Chemistry Catalysis law.invention Metal chemistry.chemical_compound Montmorillonite chemistry law visual_art Bentonite visual_art.visual_art_medium Hydroxide Calcination Clay mineral X-ray diffraction
Zdroj:	Catalysis Letters. 18:235-241
ISSN:	1572-879X 1011-372X
Popis:	Controlled calcination of ion-exchanged Texas montmorillonite leads to layer charge reduction. Detailed chemical analyses of both exchangeable and unexchangeable metal species lead to the conclusion that, in complete contrast to the situation with Wyoming bentonite, Ni2+, Co2+ and Zn2+ are all capable of migrating from the interlamellar space into the octahedral region of the sheets where they are (i) isomorphously exchanged for Mg2+, and to a proportionately smaller extent, for Fe2+, (ii) trapped in the octahedral vacancies. In addition, they are converted to unexchangeable species on the interlamellar sheet surfaces by high temperature hydrolysis leading to hydroxide or oxide formation. It is suggested that protons within the octahedral region are bound as -OH+2rather than simply physically trapped.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c83d873764b4832720c8e86c7c5aa30e https://doi.org/10.1007/bf00769442 Zobrazit plný text záznamu Full text from SpringerLink